| 摘要 |
PURPOSE:To provide a condensing device which can make the spot diameter of a light beam smaller than a light condensing device using a refraction body. CONSTITUTION:The condensing device 10 includes a liquid crystal member 20 including first and second liquid crystal areas 24 and 26 in which a crystal characteristic is formed so as to be freely changed. The first and the second areas 24 and 26 are formed between transparent electrodes 16 and 18. When a desired voltage is impressed between the electrodes 16 and 18, desired phase difference is generated between the light beam transmitted through the area 24 and a laser beam transmitted through the area 26. Then, the spot diameter and the intensity of the light beam transmitted through two areas can be changed to a desired value. |
